Today’s Polls, 6/23

We have three Rasmussen Reports polls to kick off the week, the most intriguing of which is in Pennsylvania, where Barack Obama leads John McCain by 4 points. That’s a slight improvement for Obama from Rasmussen’s May poll, when he had led by 2. Nevertheless, Rasmussen shows Pennsylvania tighter than some other polling of the state.

The operative question about Pennsylvania is whether John McCain should make a serious effort to compete there. The way to evaluate this is not by looking at the Pennsylvania numbers in the abstract, but by comparing them to the national averages. Presently, we project Barack Obama to win Pennsylvania by 8.3 points, but we also show him winning the entire election by 5.2 points. That means that if the race tightens to a draw — and it’s only when the popular vote is very close that electoral math matters — we’d expect Pennsylvania to be in the range of Obama +3. That’s close enough such that it’s too early for McCain to write Pennsylvania off entirely. A lot of things will have to go right for McCain to win Pennsylvania, but then again, a lot of things will have to go right for him to win this election.

The New Mexico result is Obama +8; he had been ahead by 9 in Rasmussen’s May poll. One thing to keep in mind is that, while we focus a lot on trendlines within any one given agency’s polling, the comparison to other pollsters does matter too. Thus, while Obama lost a point in New Mexico relative to Rasmussen’s previous poll, our win percentage for him went up there, since an 8-point lead is still much comfier than other pollsters have seen the state. Conversely, even though Obama gained in Pennsylvania relative to Rasmussen’s previous poll, his win percentage went down there, since Rasmussen continues to see the state much tighter than agencies like Quinnipiac.

Finally, in Utah, Rasmussen has John McCain ahead by 19 points. Utah is probably interesting only insofar as trivia questions go. When Bill Clinton won the election in 1992, Nebraska was his worst state, which he lost by “only” 17.2 points. That was the best worst state for a winning candidate since FDR, assuming that you count the District of Columbia as a state. The modern record, however, appears to be held by Woodrow Wilson, who lost no state by more than 11.6 points in the three-way election of 1912. If Obama has an exceptionally good election night, it is conceivable that he could threaten some of those records, but Utah will almost assuredly be his limiting factor.

Nate Silver is the founder and editor in chief of FiveThirtyEight. @natesilver538